Financial institutions have established various processes and associations related to the exchange of documents evidencing monetary transactions. Such documents have generally been encoded with magnetic ink so that information from the documents can be read by machine. Such documents have thus become known as magnetic ink character recognition (MICR) documents. Item processing and sorting systems have also been developed in which a check or similar MICR document has its image captured and stored electronically.
In a typical item processing environment, based on the read of the MICR data, items are sorted into pockets as “on-us” items or “transit” items. An on-us item is an item that is drawn on the financial institution doing the processing. On-us items will typically be forwarded to other locations within the financial institutions own franchise. Transit items are checks drawn on other financial institutions, and are pocketed for delivery to those institutions. Images are also stored and indexed for retrieval. Historically, these images have been used mainly for archival purposes; however, the image is gradually replacing the physical item for more and more purposes. For example, customers can retrieve images of their checks on-line as opposed to obtaining a copy of the actual paper item. Legislation has also been promulgated in some jurisdictions that will allow banks to reconcile accounts using electronic images instead of paper items. Thus, correct indexing and identification of images relative to corresponding MICR data can be very important.
In a modern, computerized item sorting facility, an item processing computer system controls the operation of a sorter or sorters, and the storage of data and images. Images are stored in a check image archive. Each image is indexed according to an image key which typically includes the date, sorter information, and an item sequence number (ISN). In a typical system the ISN is restricted to a specific number of digits or places. Thus, when the number of checks to be processed on a sorter in one day (also called a “cycle”) includes more than the number that can be counted with that number of digits, the ISN will begin to repeat, resulting in duplicate keys, mismatched images and other errors which disrupt the sorting operation.